This invention relates to sealing means for filter envelopes, such as those employed in treating used cooking oil. More particularly, this invention relates to a sealing means for filter envelopes wherein the sealing means is attached to the filter apparatus.
In a typical frying operation, large quantities of edible cooking oils or fats are heated in pans or vats to temperatures of from about 315xc2x0 F. to about 400xc2x0 F. or more and the food is immersed in the oil or fat for cooking. During repeated use of the cooking oil or fat, the high cooking temperatures, in combination with water from the food being fried, cause the formation of free fatty acids (or FFA). An increase in the FFA decreases the oil""s smoke point and results in increasing smoke as the oil ages. In addition, the cooking oil may include solid impurities, such as, for example, small pieces of the food being cooked.
In addition to hydrolysis, which forms free fatty acids, there occurs oxidative degeneration of fats which results from contact of air with hot oil, thereby producing oxidized fatty acids (or OFA). Heating transforms the oxidized fatty acids into secondary and tertiary by-products which may cause off-flavors and off-odors in the oil and fried food.
Caramelization also occurs during the use of oil over a period of time, resulting in a very dark color of the oil, which, combined with other by-products, produces dark and unappealing fried foods.
Such solid and dissolved impurities in general are removed from such used cooling oils by passing such oils through a filter. Such a filter includes one or more of the following components including, but not limited to, screens, metal spacer grids, filter papers, filter pads, or combinations thereof. In connection with the filter, the oil may be contacted with a variety of materials of filter aids, adsorbents, or neutralizing agents, generally in the form of powders or particles, to remove free fatty acids, oxidized fatty acids, and other by-products from the oil. Such materials include, but are not limited to, magnesium silicate, diatomite, calcium silicate, and alkali materials such as alkaline earth metal hydroxides, alkaline earth metal oxides, alkali metal carbonates, alkali metal bicarbonates, alkaline earth metal carbonates, and alkali metal silicates. Such materials may be placed upon the filter or contained within the filter. For example, when a filter pad or filter paper is employed, such materials may be impregnated in the filter pad or filter paper.
One example of a filter includes a metal spacer grid which is contained within a filter paper envelope or a filter pad envelope. The paper or pad envelope may be impregnated with a filter aid, such as those hereinabove described. Such a filter in general is disposed at the bottom of a pan of used cooking oil. The metal spacer grid has a fitting which extends from the grid through a panel of side of the filter envelope. The fitting may be connected to a pipe which is connected to a pump. When the pump is activated, the oil flows through the paper envelope on both side of the filter, through the interstices of the metal spacer grid, and through the metal fitting and pipe. The filtered oil then may be recycled for further cooking.
The filter envelope has an opening which, in general is sealed with a sealing clip. The clip, in general, is necessary for proper operation of the filter apparatus because, without the clip, food particles can bypass the filter paper or filter pad and enter the open end of the filter envelope. The sealing clips, however, are not attached to the filter apparatus. As a result, the clips often are lost or discarded accidentally by the user.
It is therefore an object of the present invention to provide a sealing means for a filter envelope wherein the sealing means is attached to the filter apparatus.
Thus, in accordance with an aspect of the present invention, there is provided a sealing means for sealing a filter envelope of a filter apparatus. The sealing means includes at least one clip means for sealing the filter envelope, and at least one connecting means extending from the filter apparatus to the at least one clip means.
In one embodiment, the connecting means includes a loop portion attached to the filter apparatus, and at least one leg portion extending from the loop portion to the at least one clip means. In a preferred embodiment, the sealing means includes at least two clips, and the connecting means includes a loop portion and two leg portions. Each of the leg portions extends from the loop portion to a clip. In a more preferred embodiment, the sealing means includes two clips and the connecting means is a wire. Each of the two clips includes a channel portion and a flange portion. The channel portion is capable of receiving the filter envelope, whereby the clip seals the filter envelope. The flange portion of each clip includes an opening for receiving a leg of the wire, whereby the clip is connected to the wire. The wire includes a loop portion, which in general surrounds a pipe or conduit of the filter apparatus. Extending from the loop portion are two legs of the wire. Each leg of the wire passes through the opening in the flange of one of the clips, whereby each of the clips is attached to the wire. Preferably, a stabilizing bar is welded to each leg of the wire such that the acute angle formed by the legs of the wire is maintained. The legs of the wire and the stabilizing bar form an isosceles triangle. Thus, Applicant has provided a means for sealing a filter envelope in which the sealing portion will not be discarded accidentally.
In another embodiment, the connecting means includes a loop portion attached to the filter apparatus, and at least one leg portion extending from the loop portion to one clip means. In a preferred embodiment, the sealing means includes a clip, and the connecting means includes a loop portion and two leg portions. Each of the leg portions extends from the loop portion to an end of the clip. In a more preferred embodiment, the sealing means includes one clip and the connecting means is a wire. The clip includes a channel portion and a flange portion. The channel portion is capable of receiving the filter envelope, whereby the clip seals the filter envelope. The flange portion has two openings located proximal to opposite ends of the clip. Each opening receives a leg of the wire, whereby the clip is connected to the wire. The wire includes a loop portion, which in general surrounds a pipe or conduit of the filter apparatus. Extending from the loop portion are two legs of the wire. Each leg of the wire passes through an opening in the flange at one end of the clip, whereby the clip is attached to the wire. Preferably, a stabilizing bar is welded to each leg of the wire such that the acute angle formed by legs of the wire is maintained. The legs of the wire and the stabilizing bar form a isosceles triangle.